Suspended ceiling system



July 14, 1959 s. E. SORENSON SUSPENDED CEILING SYSTEM 2 Sheets-Sheet 1 Filed July 31, 1956 INVENTOR.

BY STANLEY E4 SORENSON 5 ATTORNEYS- July 14, 1959 s. E. SORENSON SUSPENDED CEILING SYSTEM 2 Sheets-Sheet 2 Filed July 31, 1956 INVENTOR.

STANLEY E.SOREINS ON flzz ATTORNEYS Unitfrd S at Patent SUSPENDED CEILING SYSTEM- Stanley E. Sorenson ,Seattle, Wash. Application July 31, 1956, Serial No. 601,262 23 Claims. (Cl. 20 4) The present invention relates to suspended ceiling. systems in which the expanded ceiling is made-up of multiple panels such as acoustical tiles and the suspension means is completely hidden from view from below. This application is a continuation-in-part of my copending application, Ser. No. 464,431, filed October 25,. 1954.

The present architectural trend is toward overhead application of utility lines in the space above asuspended ceiling. Access to power or telephone wires, plumbing, etc., in this space is obviously required on occasion. Also, it is commonly desired to shift the ceiling lights to better meet the requirements of new tenants. Thus, the advantages attendant upon providing individual removal of the ceiling tile without damaging them are considerable.

In the past the only system which have permitted ready individual removal and replacement of suspended ceiling tile or panels have had a part of the suspension system exposed to viewfrom' below, the best known of these prior systems being characterized in that the edges ofthe' tile rest on exposed flanges provided by grid members having a generally inverted T-secti'on. The exposure of these flanges or, in fact, the exposure of any part other than the face of the tile itself is normally considered to be highly objectionable from an ornamental standpoint. Having the foregoing mind it is a p'rincipal object of the inventionto provide a practical ceiling suspension system which corrects this obvious defect in the systems commercially common today without unduly complicating the' supporting grid and without "necessitating the use ofspecial tools.

Other more particular objects and advantages will, togetherwith this general object, appear and be understood in the course ofthe following description and claims, the

invention consisting in the novel construction and in the adaptation and combination of parts hereinafter describedand claimed.

In the accompanying drawings:

Fig. l is a top perspective view, partly in vertical section, illustrating my system in operation andwith one" tile partially removed.

Fig. 2 is an enlarged fragmentaryvertical sectional view takenas. indicatedby line 22 of Fig. 1 andstill in top'perspective.

Fig. 3 is an; enlarged: fragmentary vertical sectional view taken asindioatedby line 3-3 of Fig. 1.

Fig. 4 is a fragmentary topr perspective view of one of the end hangers.

Fig: 5. is a view taken as Fig. 3 and illustrating a modified hanger and runner.

Fig. 6 is a top perspective view, partly in vertical sectionillustrating an alternative system for longertiles in operation and. with one tile partially removed.

Fig. 7 is an enlarged fragmentary vertical sectional view taken generally as indicated by line 7-7 of Fig. 6 i

and still in. top perspective.

Fig. 8. is an. enlarged fragmentary vertical sectional view taken along; one of the side hangersl in theceiling 2 installation and with the runner in transverse vertical section.

Fig. 9 is a transverse vertical sectional view through a side joint taken as indicated by line 9-9 of Fig. 8. Fig. 10 is a fragmentary top perspective view of one or the side hangers.

Referring to the drawings it is seen that I have illustrated my invention as applied to the suspension or acoustical panels or tiles 9 each of which is provided at least two opposite edges thereof with a groove or kerf it}. This kerf separates a top lip 11 from a bottom lip' 12 and it will be noted that the tile has been backcut such that the top lip 11 has somewhat less projection than the bottom lip 12. Accordingly, when the juncture or joint of two abutting tiles is viewed in vertical cross-section, the opposed kerfs It and resulting horizontal ga'p lie-f tween the shorter top lips 11 give a cutout of inverted T-shape for receiving suspension apparatus.

Before detailing this apparatus, it will be noted that my suspension system may utilize conventional chmnh'el headers 13, commonly known as lathers channel, which are regularly spaced in parallel relation across the ceiling space and are suspended from the overhead mueture as by hanger wires 14. Clamped to and beneath these headers by wire clips 15 are runners 16 of a general channel configuration. The clips 15 are formed of single strands of wire and are of general U-s'hape for straddling a header 13. At its ends each clip has foot prolongations 17 bent back at an acute angle to the plane" of the clip proper. As best shown in Fig. 3, these feet 11 are adapted to grip a generally l -shaped upper step 18" formed in runner 16 and press the edges of the step up against the underside of a header 13.

Continuing to further details of the runner 16, it is seen that each is of a general channel shape having a stepped upper flange formed by upper step' 18 and a flat lower step 19, a lower flange 20, and an upright web or center section 21 extending between the lower step and the lower flange 20. The latter is designed to fit into the kerf 10 along the back edge of a tile and en gage the underside of the respective top lip 11 to support the back end of the tile. For a purpose which will be hereinafter brought out in course of describing the pro cedural steps incident to applying the tile to and remov ing the tile from their ceiling positions, the vertical width ofthe kerflO into which the lower flange Zllis received is intentionally greater than, the thickness (gauge) of the To support the opposite or front end of the tiles there are provided end hangers 22 of a enerany Z-shape cross-sectionally speaking. Each of these harigy ers has a bottom horizontal flange 23 complementingithe I lower flange 20 of the runners; a central standing flange 24, and a top horizontal flange 25 directed oppositely to:

its bottom flange 23 for seating in the lower step 19 of hanger will not rock relativeto the tile and so that the hanger and tile can be handledas a unit during ap'plica tion of the tile.

ness of the bottom flange 23 of the hanger slightly greater than thethickness of the kerf to assure a snug fit of the hanger with the tile.

. upper faces'of the bottom. runner' 'and hanger flange's Z'O,

Patented July 14, 1959 In this regard; if the tile material is quite soft,- it maybe desirable to have the efiective thick The distance between the under face of the top hanger flange 25 and the upperface of the bottom hanger flange 23' is made equal 6 the distance between the upperfaces'ofthe lower runnei step and the bottom runner flange. as's'iires that the' 23, respectively, will be at the same level when the top hanger flange 25 rests on the lower step 19. In this latter regard, the steps 18, 19 should have a vertical spacing exceeding the thickness of the top hanger flange 25 so that the latter is free to move lengthwise along the lower step 19 and the supporting runner 16 and beneath the channel headers 13 to which the runner is clipped. The central flange 24 of the hangers may be dimpled as at 27 in the direction of the upper flange 25 to aid in a proper spacing of the central flanges of the hangers and runners. Related to this spacing is the fact that for best stability it is desirable to have the central hanger flange 24 bear against the free end of the top lip '11 of the tile into which the hanger is fitted.

To erect my suspension system the headers 13 are first suspended as by the wire hangers 14 in parallel level relation at intervals normally from two to four tile widths. The runners 16 are then secured by the clips to the leaders in crosswise relation thereto and separated the width of one tile from each other. With the headers and runners thus fixed in position, the next step is the actual installation of the tiles 9. It is normally the easiest procedure to insert the hangers 22 in the tiles first before raising them to the ceiling. To install a tile and hanger assembly it is first tilted at an angle with the hanger uppermost so as to clear the runners, and the assembly is then raised through the opening between two runners until the kerf at the lower edge of the tilted tile is on the same level as the bottom flanges 20 of the runners. For ease of description consider the front face of a runner as being the face of the central flange 21 from which the flange 20 projects and the back face as being the other face of the central flanges, and let the hanger end of the tile be termed the front end thereof. Also, let the runner which lies proximal to the elevated front end of the tilted tile now under discussion be termed the front runner, and the runner which lies proximal to the lower back end of the tile be termed the back runner. With the tilted tile elevated with its hanger as aforesaid, the applicator slips the kerf 10 of the tiles back edge onto the bottom flange 20 of the back runner as shown in Fig. 2. Then he allows the front end of the tile with its hanger to drop into place, the central flange 24 of the hanger sliding downwardly relative to the back face of the front runner until the hangers top flange 25 comes to rest upon the lower step 19 of the front runner. In the course of this downward movement of the hanger-carrying front end of the tile, it will be apparent that the tile will have performed a swinging action with the fulcrum of the pivot being the lower edge of the top lip 11 at the back end of the tile. This fulcrum gradually moves rearwardly along the upper face of the lower flange 20 of the back runner as the tile pivots to a level position. The significance of [having the vertical width of the kerf 10 greater than the thickness of the bottom runner flange 20 which is received therein will now be apparent, the greater Width permitting the tile to partake of such pivotal action. The tile should then be adjusted horizontally so that the back edge of the bottom lip 12 at the back end of the tile will project rearwardly slightly beyond the back face of the back runner. This slight projection is shown in Fig. 3. At the same time the backcut of the overlying upper lip 11 must be sufficient to provide enough gap between the lip and the front face of the related back runner to permit the tile to be tilted at its front end should it be later desired to remove the tile by reversing the application procedure.

Referring to Fig. 1 it can be seen that any tile which lies in part beneath a header 13 must be first placed in position alongside of the header and then be slid sidewise with its hanger along the lower step 19 of the front runner and with the top lip 11 of its back end along the bottom flange 20 of the back runner to bring the tile beneath the header 13.

Thus it is seen that if access is required to the space above one of the tiles 9, the tile can be readily removed by reversing the installation procedure, and namely by pushing up the front or hanger-carrying end of the tile to elevate the related hanger 22 free of its runner 16 and then shifting the tile forwardly while in its tilted position so as to free the back edge of the tile from the bottom flange 20 of the other supporting runner. If the tile to be removed lies partially beneath one of the headers 13 it is necessary to first remove one of the tiles against which its side edges abut, shift the tile sidewise from beneath the header, and then remove it as just described.

In Fig. 5 I have illustrated a modified runner 16a and end lhanger 22a in operative position. Like the runners 16, the runner 16a is generally channel shaped having a bottom flange fitting loosely in the kerf 10 at the back end of a tile, an upstanding central section 121, and a stepped top flange. At its outer or front side the latter has an upper step 118 which is the same as the step 13 and is gripped by the feet of a clip 15 to be held thereby against a header 13. Accordingly, it will be seen that the only difference between runners 16a and 16 resides in the bottom step 119 of the top flange, and namely in the fact that this step slopes downwardly from the top of the central section 121 toward the upper step 118 instead of being horizontal.

Hanger 22a is generally Z-shaped and at its upper end has a downwardly sloping flange or locking lip complementing the sloped lower step 119 of the runner 16a. Continuing from this upper flange the hanger 22a has a section 239 which extends downwardly, then slopes backwardly away from the upper flange 125, and then continues downwardly to intersect a lower flange 123 corresponding to the lower flange 23 of hanger 22. This lower flange 123 is generally V-shaped with the vertex of the V being lowermost and offset toward the free back edge of the flange. The depth of the V corresponds to the depth of the dished portions 26 in the lower hanger flange 23, the purpose of the V being to fill the kerf 10 into which the hanger is inserted.

The manner of installation of the modified runner 16a and end hanger 22a is the same as that aforedescribed for runner 16 and hanger 22, and it will be apparent that other changes in shape can be made in the parts of the system without departing from the basic teachings of the invention.

Some accoustical tiles are produced elongated such as a 12 x 24 inch size. Many makes of these tiles will unduly sag if only supported at their ends, but will support their own weight satisfactorily across their width. Such a tile has been designated 9a in Fig. 6 and is illustrated with a modified suspension system which will now be described. This modified system incorporates the same runners 16, clips 15, and headers 13, the change being the use of a pair of side hangers instead of an end hanger 22. Such a pair consists of complementing right and left hand members designated 222R and 222L, respectively. At their front ends these members have top flanges 225 for seating on the lower step 19 of a runner 16 in the same manner as flanges 25 of the end hangers 22. Extending downwardly from these top flanges 225 are central sections 224 corresponding to end hanger sections 24, and extending rearwardly from the latter are bottom flanges 223 which correspond functionally to end hanger flanges 23 in that they are fitted into the tile. For this purpose tile 9a has a kerf 210 extending therearound forming continuous top and bottom lips 211, 212, the former being backcut in the same manner as top lip 11 of tile 9. For clarity the long edges of tile 9a will be referred to as the sides and the short edges as the ends. Examining Figs. 6-9 it is seen that bottom flange 223 has a Width no greater than the depth of kerf 210 and a length slightly less than the length of tile 9a. Furthermore, flange 223 desirably is downwardly dished at intervals to form cups 226' whose function i n w issto; fill ther kerf in. the same 1113111161: as the. dished. por= tions: 26 of the end. hangers 22. To longitudinally strengthen the-.sidehangers the right and lefthandsides ofrhangers 222R andZZZL, respectively are provided with upstanding reinforcing flanges. 250 which are joined to tlie.:respective side edges of the hangers bottom flanges 223. Thus it is seen that these side hangers can be formed from a single. sheet of material.

Inpreparing for the installation of .tiles9a the runners 1-6:arespaced apart the length of the tiles and clipped implaceto the headersxas before. A pair'of side hangers istthen inserted intothe. kerfs 210 along the side edges ofi thes tile. 9a to be applied and with the centralstanding sections 224 of the hangers resting against the front edge ofl'the top lip 211 at the front end of the tile. The latter isnthentilted. withits front end upward and raised between: .thefront and back runners by whichit is to be supported. Then the back edge of the tile is eased toward the bottom flange of the back runner to bring therear end portions of the side hangers bottom flanges 223"torest on flange 20. The forward end of the tile is thenlowered to bring the side hanger flanges 225 torest 0n=the lower step 19 of the front runner. During this lowering action the rear ends of the side hangers act as a pivot and at-the same time work further onto the bottom flange 20 of the back runner to give longitudinal support to the tile. In this regard the vertical thickness of the kerf 210 must be sufficiently greater than the combined thickness of runner flange 20 and side hanger flange 223 to permit the pivotal action of the tile. The tiles-9a and their side hangers can be shiftedsideways along the runners the same as tiles 9-and their end hangers to bring them beneath a header 13. As in the caseof the end hangers, it can be readily understood that a tile equipped with side hangers is removed by reversal of its installation procedure.

Referring to Fig. 9 it is seen that the reinforcing flanges 250 of the side hangers are desirably ribbed outwardly in theopposite direction from therespective bottom flanges 223 so that there will be a line sealing contact at the joint between adjacent hangers. This sealing contact can be aided by slightly canting the top hanger flanges 225*sothat the top flanges of each pair of side hangers tend to slope downwardly toward one another.

The advantages of the invention, it is thought, will have been clearly understood from the foregoing detailed description of the illustrated preferred embodiments. Minor changes will suggest themselves and may be resorted to without departing from the spirit of the invention, wherefore it is my intention that no limitations be impliedand that the hereto annexed claims be given a scope'fully commensurate with the broadest interpretation to which the employed language admits.

What Iclaim is:

1. In a ceiling suspension system, a runner having a bottom support flange and a top flange spaced thereabove and stepped to provide a lower step and an upper step, and a' hanger completely located no higher than the uppermost extremity of said upper step, said hanger having a top flange resting on said lower step and a bottom panel support flange directed oppositely from said bottom support flange of the runner.

2. In a ceiling suspension system, a generally U-shaped runner having anupright center web and having a bottom flange and a top flange joining said web, said top flange being stepped to provide an inner lower step joiningsaid web and an outer upper step, and a generally Z-shaped hanger having a top flange resting on said lower stepand a bottom flange directed oppositely from said bottom flange of the runner.

3. In a ceiling suspension system, a runner having a bottom flange. and. a top flange spacedthereabove and stepped to provide a lower step and an upper step, said upper step being generally V-shaped with its vertex downwardly and saidlower stepbeing flat, and ahanger having a flat top; flange resting: on. saidrlower step: andaa' bottomflangedirectedoppositely-fromsaidrbottom-flange of the runner;

4. In a ceiling suspension system, .a generally U-shaped runner having vertically spaced top' and bottom flanges, and a, generally Z-shaped hanger-having a topiflangeresting on said top flange of the hanger and having a bottom flange directedoppositely from said bottom flange of the runner, said bottom flanges of the. runner and hanger. having respectiveupper panelsupporting surfaces; which occupy the same plane, and said bottom flangeof the. hanger extending. below saidplane a greater amount than said bottom flange of the runner;

5. Ina ceiling suspension system, a runner: having a top flange with an uppermost surface defining a header: engaging plane and said runnerlhaving a bottom: flange spaced beneath its said top flange, and a:hangerrestingon said top flange. and. having abottom flange. directedoppositely from said bottom flange: of the runner, said bottom flanges of the runner and hanger havingrespec tive upper panel support surfaces occupying a common plane which is parallel: to. said header engaging plane, and the overall thickness of thebottom 1 flange of the hanger being thicker than the overall thickness of' thezbottom flange ofthe runner.

6. In a ceiling suspension system, a generally U-shaped. runner having a. standing central section extending be-- tween top and bottom terminal flanges, said top. flange being stepped to provide an upper step along its free edge portion and a lower step merging with said. centraLsection, said upper stop being concave downwardly along its length.

7. The structure of claim 6 in; whichthe longitudinalv side edges of said upper step define. a plane which is parallel to said bottomflange.

8; In a ceilingsuspension:system, a pair of: front and back parallel spaced runners each having a. bottom support flange and a top flange. spaced thereabove and stepped to provide a lower stepand an upper step, anda hanger having a top flange at its front endresting. on said lower step and located no higher than'the uppermost extremity of saidrupper step of said front runner andhavingan elongated bottom panel support-flange restingsby its back end on said bottom support flangeof said. back. runner.

9. The structure of claim 8in1which said bottom flanges of the front and back runnerswhave. respective supportsurfacc's-which occupy the 'same; plane and in which said bottomflange of the hanger extends below said plane a greater amount than said-bottom flanges of the runners.

10.. In a ceiling suspensionsystem, a pair offront and back parallel spaced.runnerseachzhaving an uppermost forwardly directed header: engaging surface and a lowermost forwardly directed support flange spaced therebeneath, each ofsaid runners havingra shelf between its said surface andflange whichis unobstructed above by other structure of the runner, and a panel assembly having hanger means projecting forwardly at the front thereof and resting on said shelf of the front runner, the forwardly projecting portion of said hanger means being completely located nozhignerthansuch shelf, said panel assembly having a loose tongue-and-groove inteifit'with said bottom flange of the back runner and covering the underside of such runner, the looseness of said interfit being sulflcient to permit the front end' of said panel assembly to be pivotedup-wardly fromsaid front runner through an. are large enough to allow the rear end of the tilted panel assembly'to be freed of its said interfit with said bottom flange of the back runner.

11. In a ceiling suspension system, a generally U shaped runner having an uprightcenter web and having a bottom flange and a top flange joining said web, said top flange being stepped to provide an inner lower step joining. said web and an outer UPIJGIL step, a generally Z- shapedrhanger having a top flange resting on said-lower' step and an elongated bottom flange directed by its length oppositely from said bottom flange of the runner.

12. The structure of claim 11 in which a strengthening lip extends upwardly from one of the longitudinal side edges of said elongated bottom flange of the hanger.

13. In a ceiling suspension system, a generally U-shaped runner having vertically spaced top and bottom flanges, and a generally Z-shaped hanger having a top flange resting on said top flange of the hanger and having an elongated bottom panel support flange directed by its length oppositely from said bottom flange of the runner, said panel support flange of the hanger extending by its underside lower than said bottom flange of the runner and having its upper side higher than the latter said flange.

14. In a ceiling suspension system, a pair of front and back parallel spaced runners each having an upright web section and a forwardly directed bottom flange at the bottom of said web section, and a set of right and left parallel spaced hangers resting by their front ends on said front runner and each having an elongated bottom flange resting by its back end on said bottom flange of said back runner, and a panel formed with side kerfs receiving said bottom flanges of said hangers for support of the panel, said panel having its front end located rearwardly of the bottom of said front runner and having its back end formed with a bottom lip covering and spaced below the underside of said back runner by a gap which is large enough to permit the front end of said panel to be sufflciently pivoted upwardly together with said hangers from said front runner about the back ends of the hangers as pivots, to allow the rear end of said bottom lip and the rear ends of said hangers to be freed from said bottom flange of said back runner.

15. In a ceiling suspension system, a pair of front and back parallel spaced runners each having an upright web section and a forwardly directed bottom flange at the bottom of said web section, and a set of right and left parallel spaced hangers resting by their front ends on said front runner and by their back ends on the bottom flange of said back runner, each of said hangers having an elongated bottom flange intermediate said runners, and a panel formed with side kerfs receiving said bottom flanges of the hangers for support of the panel, said panel having its front end located rearwardly of the bottom of said front runner and having a back end portion covering and spaced below the underside of said back runner by a gap which is large enough to permit the front end of said panel to be sufliciently pivoted upwardly together with said hangers from said front runner about the back ends of the hangers as pivots, to allow said rear end portion of the panel and the rear ends of said hangers to be freed from said back runner.

16. In a ceiling suspension system, a pair of front and back parallel spaced runners each having an upright web section and a forwardly directed bottom flange at the bottom of said web section, and a set of right and left parallel spaced hangers resting by forwardly projecting front end portions on said front runner and by their back ends on the bottom flange of said back runner, each of said hangers having panel support means intermediate said runners, and a panel formed with side kerfs receiving said panel support means, said panel having its front end located rearwardly of said front runner and said projecting front end portions of the hangers and having a back end portion covering and spaced below the underside of said back runner by a gap which is large enough to permit said projecting front end portions of the hangers to be sufliciently pivoted upwardly from said front runner about the back ends of the hangers as pivots, to allow said rear end portion of the resulting tilted panel and the rear ends of the tilted hangers to be freed together from said back runner.

17. In a ceiling suspension system, a pair of front and back parallel spaced runners each having an upright web section and a forwardly directed bottom flange at the bottom of said web section, and a set of right and left parallel spaced hangers resting by forwardly projecting front end portions on said front runner and by their back ends on the bottom flange of said back runner, each of said hangers having a general L-section between said runners providing a panel support flange directed toward the other hanger and an upright reinforcing flange, and 'a panel formed with side kerfs receiving said panel support flanges and with backcuts above said ker-fs for passage of said reinforcing flanges, said panel having its front end located rearwardly of said front runner and having a rear end portion covering and spaced below the underside of said back runner by a gap which is large enough to permit said panel and hangers to be pivoted upwardly together about the back ends of the hangers as pivots, and thereby raise said projecting front end portions of the hangers relative to said front runner sufliciently to enable said rear end portion of the panel and the rear ends of said hangers to be freed from said back runner.

18. In a ceiling suspension system, a runner having a bottom flange with an upper support surface, and a hanger having a top flange at one end resting on said runner at a level above said upper support surface and having an elongated terminal bottom flange directed by its length oppositely from said bottom flange of the runner for supporting a panel, the underside of said terminal bottom flange being interrupted along its length by downwardly depressed portions all of which are spaced toward the runner from the free end of the terminal bottom flange, said depressed portions depending to a level lower than that of the underside of said bottom flange of the runner with the remainder of said underside of said terminal bottom flange having a level corresponding to the level of said upper support surface.

19. In a ceiling suspension system, a runner having a forwardly directed bottom flange with an upper support surface, and a fore-and-aft extending elongated;

hanger resting by its front end on said runnner at a level at least as high as said upper support surface and having an elongated panel support bottom flange extending rearwardly of said runner to the terminal back end of the hanger, said panel support bottom flange being interrupted along its length rearwardly of said runner by a. downwardly depressed portion spaced forwardly from said back end of the hanger a distance at least as great as the fore-and-aft width of said upper support surface, said depressed portion depending to a level lower than that of the underside of said bottom flange of the runner with the remainder of the underside of said panel support bottom flange of the hanger having a level corresponding to the level of said upper support surface.

20. In a ceiling suspension system, a plurality of parallel spaced elongated headers having coplanar bottom surfaces, and a plurality of elongated channel-like regularly spaced parallel runners extending at cross-angles to said headers and each having a top flange and a bottom flange therebeneath interconnected by a web section, each said top flange being stepped to provide an upper step engaging said bottom srn'faces of the headers and a lower step merging with said web section for supporting a hanger, said lower step being spaced below said bottom surfaces, and clip means holding said supper steps of the runners against said bottom surfaces of the headers.

. 21. In a ceiling suspension system, an elongated support, an elongated runner disposed at cross-angles with respect to said support, said runner having a stepped flange providing an upper step and a lower step and having a central web which merges with said lower step, and means operatively associated with said support and runner for holding said upper step against said elongated support with said lower step spaced below the support for receiving a hanger.

22. The structure of claim 21 in which the longitudinal side edges of said upper step both engage said support and occupy a common plane which is at substantially right angles with respect to the plane of said central web.

23. In a'ceiling suspension system, a generally U-shaped runner having a bottom flange and a top flange which is stepped to provide a lower step and an upper step, a generally Z-shaped hanger having a top flange resting on said lower step and an elongated bottom flange directed by its length oppositely from said bottom flange of the runner, said upper step of the runner being generally V-shaped with its vertex downwardly, and said lower step of the runner and said top flange of the hanger being flat.

References Cited in the file of this patent UNITED STATES PATENTS Rader Dec. 2, Voigt Mar. 9, Ray May 11, Urbain Nov. 20, Jacobson Aug. 11, Jacobson Feb. 2,

FOREIGN PATENTS Great Britain Nov. 12, 

